Research published on April 7 shows that polar bears are altering their diets by stealing eggs and scavenging to adapt to climate change.
With global warming rates twice as fast as average, the Arctic is one of the regions most clearly affected by climate change. This caused the sea ice to shrink rapidly, shortening the polar bear’s hunting time.
With high nutritional requirements, these top terrestrial predators must travel further to find alternative food sources, including scavenging in populated areas. Some even go to bird nesting sites to steal eggs.
The study, published in the Royal Society Open Science, led by biologist Patrick Jagielski of the Great Lakes Institute for Environmental Research at the University of Windsor in Canada, tracked how polar bears approach their nesting sites on the island. from Mitivik to Nunavut for an 11-day period when the egg population was nearly depleted.
Jagielski and his colleagues discovered that the bears did not yet know how to effectively find eggs, ignoring identifying clues as obvious as the sudden arrival of the mother bird.
“Many species can incorporate ‘less desirable’ resources into their diet when primary prey becomes difficult to find, however, some other species like polar bears cannot yet do so. Effectively ”, underlines Jagielski.
About 25,000 polar bears remain in the wild, divided into 19 subgroups, spread across the arctic region from Alaska, Canada, Greenland, Norway to Russia. In July, a study published in the journal Nature Climate Change warned that most polar bears were at risk of starving to death by 2100.
Analysis of skull tooth wear shows that polar bears are highly specialized in their diet, almost exclusively hunting seals, which will cause them to struggle to adapt to global warming.
However, increased encounters between polar bears and grizzly bears – leading to crossbreeds – could provide an evolutionary option, the researchers said.
“Polar bear populations will likely have to rely on interbreeding grizzly bears to adapt to climate and environmental changes. Will they succeed in changing their hunting strategy to reduce competition with their loved ones, or will they become another victim? of the rapid extinction? of this century? “
